"Cancer appears earlier (in India) than say in China or the U.S., so it's a disease of the young," said the lead author of the paper, Professor Prahbat Jha, from the Centre for Global Health Research at the University of Toronto in Canada.

Jha said that could be because of India's younger population and the long-standing use of tobacco, which is the main cause of cancer in the country and responsible for 40 percent of cancers in men and 20 percent in women.

In men, the top three cancer killers were oral, stomach and lung cancer, while in women, they were cervical, stomach and breast cancer.

"The males have been smoking for a very long time, even longer than the Chinese and the patterns of diseases that come from prolonged smoking can occur in a population even at a younger ages," Jha told Reuters in a telephone interview.

According to The Tobacco Atlas, 26.2 percent of males in India use tobacco, either smoking or chewing it, or both. For females, 3.6 percent use tobacco and most of them chew it.

Chewing tobacco has long been linked to oral cancer, and this study found that the number of oral cancers was twice that of lung cancer in India.

Jha said the most important message from the study, which was published in The Lancet, is for India's government to increase tobacco taxes and prices substantially -- which studies have shown to be the single most effective measure to reduce smoking.

"Higher tobacco taxes are as close to an effective anti-cancer vaccine as you can get," Jha said, although he noted that the government's budget on March 16 failed to raise tobacco taxes or prices.

The study also found that cancer rates varied significantly between different states in the country and between villagers and city-dwellers.

"Cancer death rates were two-fold higher in the least educated than the most educated, and (the differences) were similar between urban and rural areas. We used to think that cancer is a luxury of the rich, it is a suffering of the poor," Jha said.

Possible explanations were that tobacco use was higher among the less educated and that richer Indians tended to seek treatment earlier.

The authors called for better health services and vaccines that can protect people against certain cancers. They predicted that if vaccines against infection by human papillomavirus (HPV) were available for girls and women in India, deaths from cervical cancer would be reduced from 33,000 to 7,000.